68515821 has 16 divisors (see below), whose sum is σ = 110733120. Its totient is φ = 41524560.

The previous prime is 68515793. The next prime is 68515841. The reversal of 68515821 is 12851586.

68515821 is a `hidden beast` number, since 68 + 515 + 82 + 1 = 666.

It is not a de Polignac number, because 68515821 - 2⁶ = 68515757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68515841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 115050 + ... + 115643.

It is an arithmetic number, because the mean of its divisors is an integer number (6920820).

Almost surely, 2^68515821 is an apocalyptic number.

It is an amenable number.

68515821 is a deficient number, since it is larger than the sum of its proper divisors (42217299).

68515821 is a wasteful number, since it uses less digits than its factorization.

68515821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230713 (or 230707 counting only the distinct ones).

The product of its digits is 19200, while the sum is 36.

The square root of 68515821 is about 8277.4284050060. The cubic root of 68515821 is about 409.1949720317.

The spelling of 68515821 in words is "sixty-eight million, five hundred fifteen thousand, eight hundred twenty-one".